The screws for assembling a thin product are always relatively small, so the torsion of the electric screwdriver for tightening the screws is also relatively small, otherwise, the excessive torsion will damage the screws. To ensure the precise setting for the torsion of the electric screwdriver, the current testing methods are hand holding of an electric screwdriver, and testing the torsion of the electric screwdriver directly on a torsion test measuring device. However, it is difficult to control the power applied to the electric screwdriver, which results in the power applied to the electric screwdriver not always being uniform.